Two-phase stainless steel, method of manufacturing the same, and diaphragm, pressure sensor, and diaphragm valve using two-phase stainless steel
AssigneeSeiko Instruments Inc.
InventorsTakuma OTOMO, Keita NAITO, Ryo SUGAWARA, Tomoo KOBAYASHI
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Abstract
It is an object of the present invention to provide a metal diaphragm capable of achieving a higher strength, excellent corrosion resistance, and a smooth surface condition, and a pressure sensor including the diaphragm. The diaphragm according to the present invention includes a two-phase stainless steel having a composition of 24 to 26 mass % Cr, 2.5 to 3.5 mass % Mo, 5.5 to 7.5 mass % Ni, 0.03 mass % or less C, 0.08 to 0.3 mass % N, and the balance Fe and inevitable impurities, and having a 0.2% proof stress of 1300 MPa or higher.
Claims13
A two-phase stainless steel having a composition of 24 to 26 mass % Cr, 2.5 to 3.5 mass % Mo, 5.5 to 7.5 mass % Ni, 0.03 mass % or less C, 0.08 to 0.3 mass % N, and the balance Fe and inevitable impurities, and having a 0.2% proof stress of 1300 MPa or higher.
A method of manufacturing a two-phase stainless steel, comprising performing working at a reduction of area of 50% or higher on a two-phase stainless steel having a composition of 24 to 26 mass % Cr, 2.5 to 3.5 mass % Mo, 5.5 to 7.5 mass % Ni, 0.03 mass % or less C, 0.08 to 0.3 mass % N, and the balance Fe and inevitable impurities, and performing aging heat treatment at a temperature of 500° C. or lower to provide a 0.2% proof stress of 1300 MPa or higher.
A method of manufacturing a two-phase stainless steel comprising performing working at a reduction of area of 83% or higher on a two-phase stainless steel having a composition of 24 to 26 mass % Cr, 2.5 to 3.5 mass % Mo, 5.5 to 7.5 mass % Ni, 0.03 mass % or less C, 0.08 to 0.3 mass % N, and the balance Fe and inevitable impurities, and performing aging heat treatment at a temperature of 500° C. or lower to provide a 0.2% proof stress of 1500 MPa or higher.
Dependencies are inferred from the claim text.